1. Field
The following description relates to an apparatus and method for radio communication, and more particularly, to a radio communication apparatus and method that may effectively use frequency resources of a radio channel during a cognitive radio communication.
2. Description of Related Art
With the rapid development of wireless technologies, radio frequency resources are becoming scarce, and a good number of the radio frequency resources in a GHz band, particularly, in a relatively low frequency band have been allocated and are used. Accordingly, increasing attention is being paid to a cognitive radio communication system in which a frequency allocated to a primary user is used by a secondary user.
In a cognitive radio communication system, a primary user and a secondary user may communicate with each other using the same frequency band. In the cognitive radio communication system, the secondary user may transmit signals using an empty frequency band that is already allocated to the primary user but is substantially unused by the primary user. However, the primary user has priority with respect to an available frequency band. Accordingly, where a signal of the secondary user may collide with a signal of the primary user, the secondary user may need to suspend a data transmission or may need to change a usage frequency band to another frequency band.
Generally, as a sensing duration to perform sensing of a radio channel is longer, a detection performance of the radio channel may be enhanced. As the detection performance of the radio channel is enhanced, it may be possible to reduce an occurrence of an abnormal situation such as a false alarm, a detection error, and the like. On the other hand, an amount of resources that the secondary user may use to perform a data communication may decrease whereby an amount of data that the secondary user may transmit may also decrease. Accordingly, there is a need for a radio communication apparatus that may retrieve an optimal sensing duration and a false alarm probability in a given environment, and sense a radio channel using the optimal sensing duration and the false alarm probability so as to enhance a channel capacity of the radio channel.